SB5J5 


Qlije  §.  ^.  ^tU  pterg 


SB555 


S00070529  N 


,    8061  'U  Nvp  •i^j 

jepuig 


NEW  HAMPSHIRE  COLLEGE 
AGRICULTURAL  EXPERIMENT  STATION 

Technical  Bulletin  No.  ii 
OCTOBER,  191(> 


NOTES  ON 

THE  PRESENCE  OF  NITRATES 

IN  ORCHARD  SOILS 


SB366 


•^i^^b'^ 


■nl 


This  BOOK  may  be  kept  out  TWO  WEEKS 
ONLY,  and  is  subject  to  a  fine  of  FIVE 
CENTS  a  day  thereafter.  It  is  due  on  the 
day  indicated  below:  4S^^*^ 


NEW  HAMPSHIRE  COLLEGE 
AGRICULTURAL  EXPERIMENT  STATION 

Technical  Bclletin  No.  ll 
OCTOBER,  1916 


NOTES  ON 

THE  PRESENCE  OF  NITRATES 

IN  ORCHARD  SOILS 


::.'^ 


BY 


J.  H.  GOURLEY  and  V.  D.  SHUNK 


NEW  HAMPSHIRE  COLLEGE 

OF 

AGRICULTURE  AND  THE  MECHANIC  ARTS 

DURHAM.  N.  H. 


•W^^^ 


NOTES  ON  THE  PRESENCE  OF   NITRATES   IN 
ORCHARD    SOILS. 

By  J.  H.  GouRLEY  AND  V.  D.  Shunk. 

Much  has  been  written  on  tlie  various  cultural  systems  used 
in  apple  orchards  and  considerable  data  have  been  presented  to 
show  the  effect  of  each  of  the  systems  on  the  growth  and  yield 
of  the  trees.  Some  general  recommendations  are  now  considered 
standard  and  are  in  common  use,  e.  g.,  most  authorities  agree  that 
to  grow  trees  in  sod  is  usually  not  a  good  practice  but  that  the 
grass  mulch  system  is"  a  perfectly  practical  method  of  culture 
especially  when  accompanied  by  the  use  of  fertilizers.  There  is 
also  general  agreement  that  tillage  in  the  orchard  is  quite  bene- 
ficial and  will  stimulate  growth  and  increase  production,  and  when 
the  use  of  cover  crops  accompanies  it  the  value  is  enhanced. 
Some  information  is  also  at  hand  to  show  the  effects  of  these  sys- 
tems on  the  soil  but  all  mooted  questions  in  this  regard  do  not 
appear  to  be  satisfactorily  answered. 

It  is  the  purpose  of  this  paper  to  present  some  additional  data 
showing  the  effect  of  sod  and  tillage  on  the  presence  of  nitrates 
in  the  soil,  and  to  partially  correlate  these  with  the  behavior  of  the 
trees  as  regards  yield  and  growth.  Primarily  the  writers  are 
interested  in  determining  some  of  the  reasons  why  trees  behave 
differently  under  different  cultural  treatments  and  why  fruit 
buds  are  formed  with  abundance  when  grown  under  a  good  system 
of  culture  and  greatly  reduced  when  grown  in  sod  land  without 
fertilizers  or  tillage.  The  observations  here  reported  are  made 
as  a  corollary  of  such  a  study. 

In  Technical  Bulletin  No.  9,  N.  H.  Elxperiment  Station,  the 
senior  author  makes  the  statement  that  the  formation  of  nitrates 
is  greatly  reduced  in  a  sod  orchard.  But  the  evidence  presented 
at  that  time  showed  only  that  less  nitrates  were  recovered  in  our 
soil  samples  during  the  growing  season  under  sod  than  where 
tillage  was  practiced,  and  therefore  would  not  show  conclusively 
that  nitrification  was  not  active  under  sod,  but  rather  raise  the 
question  whether  the  grass  and  trees  together  did  not  use  up 


noFEimr  library 
N.  C  State  CoIUrp     4275^ 


4  N.    H.    AGE.    EXPERIMENT   STATION.  [Bulletin  11 

such  an  excessive  amount  of  nitrates  that  little  accumulated  as 
an  excess  or  as  a  residual  in  the  soil. 

At  the  outset  it  is  well  to  state  that  the  assumption  is  not  herein 
made  that  the  presence  or  absence  of  large  amounts  of  nitrates 
is  the  sole  cause  of  vigorous  growth  or  the  reverse,  for  without 
question  other  factors  are  of  great  importance.  Aeration  in 
itself  has  doubtless  a  beneficial  effect  other  than  increasing 
nitrification,  for  the  oxidation  processes  may  make  available 
other  forms  of  plant  food  materials  and  also  encourage  a  beneficial 
soil  flora.  Just  how  much  these  various  cultural  treatments 
furnish  additional  nutritive  material  and  how  much  they  may 
be  of  a  "sanitary"  value  cannot  be  fully  stated. 


THE  ORCHARD. 

The  work  here  reported  has  been  conducted  in  a  mature 
Baldwin  apple  orchard  of  nine  acres  which  was  acquired  for  the 
purpose  of  experimentation  in  1908.  Prior  to  that  time  the 
orchard  was  in  grass  and  the  hay  cut  and  removed  each  year 
until  it  was  in  a  weakened  and  unproductive  state.  Ten  plots 
were  laid  out  with  a  division  row  l^etween  each  so  that  the  in- 
fluence of  one  plot  would  not  extend  over  to  an  adjoining  one. 
The  orchard  is  quite  level  and  the  soil  fairly  uniform  but  the 
plots  are  somewhat  lighter  on  one  end  than  on  the  other. 

CHARACTER   OF  THE    SOIL. 

Of  the  ten  plots  in  the  orchard  we  are  interested  at  this  time 
in  three  only,  Nos.  1,  4  and  5,  none  of  which  have  been  fertilized. 
The  soil  of  these  plots  is  practically  identical  and  is  therefore  well 
suited  to  a  study  of  the  comparative  amounts  of  nitrates  and 
moisture  present  under  the  different  systems  of  culture.  Later 
in  the  paper,  however,  mention  is  made  of  Plots  11  and  12  in 
connection  with  liming.  The  soil  of  those  plots  is  somewhat 
heavier  and  they  have  also  been  fertilized  as  described  below. 

A  composite  sample  was  taken  from  the  first  series  of  plots 
mentioned  and  a  mechanical  analysis  made.  The  following 
table  gives  this  analysis: 


October,  '16] 


NITRATES    IN    ORCHARD    SOILS. 


Table  No.  1. 
Mechanical  Analysis  of  Soil. 


Subsoil 
7  in. -3  ft. 


Fine  gravel,  2  to  1  mm 

Coarse  sand,  1  to  0.5  mm 

Medium  sand,  0.5  to  0.25  mm. 
Fine  sand,  0.25  to  0.1  mm.  .  .  . 
Very  fine  sand,  0.1  to  0.05  mm. 

Silt,  0.05  to  0.005  mm 

Clay,  0.005  to  0  mm 


Lyon,  FippinandBuckman*  give  the  average  analysis  of  six  fruit 
soils,  and  it  is  here  cited  for  comparison  with  the  soil  in  question: 

Fine  gravel 1.0 

Coarse  sand 6.8 

Fine  sand 42 . 0 

Silt 23.3 

Fine  silt 7.3 

Clay 10.9 

From  these  analyses  it  will  be  seen  that  the  soil  under  question 

is  of  a  distinctly  light  nature,  especially  is  the  subsoil  very  sandy 

and  therefore  such  a  soil  as  we  would  expect  to  suffer  a  rapid  loss 

of  nitrates  after  a  heavy  rain,  which  has  proven  to  be  the  case 

throughout. 

TREATMENT  OF  PLOTS. 

Plot  1.  Sod.  This  plot  has  remained  permanently  in  sod  and 
the  grass  is  cut  once  during  the  summer  and  allowed  to 
remain  where  it  falls.  No  fertilizer  has  been  applied,  and 
no  grass  mulch  is  included  in  this  experiment. 

Plot  4.  Clean  cultivation.  This  plot  is  plowed  every  spring  and 
cultivated  every  two  weeks  until  September  1.  No  cover 
crop  is  sown  and  no  fertilizer  applied. 

Plot  5.  Cultivation  and  cover  crop.  This  plot  is  plowed  in  the 
spring  and  tilled  every  two  weeks  until  July  10  when  a 
cover  crop  of  crimson  clover  is  sown,  no  fertilizer  is  applied. 

*Soils,  1915. 


N.    H.    AGR.    EXPERIMENT   STATION. 


[Bulletin  11 


Plot  11.  The  limed  plot  extends  across  one  end  of  four  fertilized 
plots  and  each  tree  has  received  an  application  of  20  pounds 
of  lime*  per  tree  for  nine  years.f  The  fertilizers  on  the 
four  plots  respectively  are  2  pounds  nitrate  of  soda,  4  pounds 
sulphate  of  potash,  8|  pounds  acid  phosphate,  per  tree;  2 
pounds  nitrate  of  soda,  4  pounds  sulphate  of  potash,  17pounds 
acid  phosphate,  per  tree;  6  pounds  nitrate  of  soda,  4  pounds 
sulphate  of  potash,  8|  pounds  acid  phosphate,  per  tree;  and 
2  pounds  nitrate  of  soda,  10  pounds  sulphate  of  potash,  8^ 
pounds  acid  phosphate,  per  tree. 

Plot  12.  For  a  check  on  the  lime  treatment  a  similar  plot  of  trees 
was  selected  which  stands  parallel  to  the  limed  plot. 


YIELD  AND  GROWTH  OF  TREES. 

These  plots  have  behaved  differently  as  regards  yield  and 
growth  since  they  have  been  under  the  influence  of  the  various 
treatments.  Therefore  it  should  be  possible  to  trace  some  of  the 
reasons  for  the  marked  and  consistent  variation  in  behavior  to 
the  effect  of  the  treatments  on  the  soil  activities. 

The  following  measurements  were  made  at  the  end  of  the  grow- 
ing season  by  taking  the  length  of  new  growth  of  twenty  twigs  which 
so  far  as  can  be  determined  are  typical  of  the  growth  of  the  tree. 
Each  tree  in  a  plot  is  thus  measured  and  the  average  growth  for  the 
plot  then  calculated. 

Table  No.  2. 

Average  Annual  Twig  Growth  Per  Tree. 
Inches. 


Year. 

Plot  1 

Plot  4 

Plots 

Sod. 

Tillage. 

Tillage  and  cover  crop. 

1909 

4.59 

6.29 

8.31 

1910 

4.15 

8.79 

10.19 

1911 

3.21 

8.43 

8.19 

1912 

4.79 

8.43 

8.92 

1913 

5.76 

9.03 

9.03 

1914 

4.70 

4.90 

6.90 

1915 

6.40 

7.18 

10.30 

Average 

4.80 

7.58 

8.83 

*65%  CaCO.,. 

tSee  Bulletin  168,  N.  H.  Experiment  Station. 


Octuber.  '16] 


NITRATES    IN    ORCHARD    SOILS. 


It  will  here  be  seen  that  Plot  1  (the  sod  plot)  has  made  an 
average  growth  of  less  than  5  inches  a  year  for  a  period  of  eight 
years,  Plot  4,  7|  inches  and  Plot  5  nearly  9  inches  (8.83  in.)  or 
nearly  twice  the  growth  of  the  plot  in  sod.  It  will  of  course  be 
understood  that  the  trees  under  cultivation  produce  many  twigs 
of  a  greater  growth  as  well  as  water  sprouts  and  excessive  growth 
in  the  tops  of  the  trees,  but  such  growth  is  eliminated  from  the 
data  and  only  the  normal  growth  at  the  ends  of  the  permanent 
branches  is  included.  Plots  4  and  5  have  been  of  special  interest 
as  the  soil  on  these  plots  is  quite  uniform  and  the  outstanding 
difference  in  treatment  is  that  Plot  5  has  a  cover  crop  plowed  in 
annually  while  Plot  4  has  had  clean  cultivation  throughout.  In 
some  years  there  was  little  difference  in  the  growth  on  these  plots 
but  the  past  two  years  the  superior  treatment  of  Plot  5  has  been 
showing.  At  this  time  we  wish  to  call  attention  to  the  greater 
amount  of  nitrates  found  each  year  in  Plot  5  than  in  Plot  4  as 
shown  in  a  later  table  which  may  explain  at  least  to  some  extent 
the  difference  in  growth.  The  moisture  content  is  slightly 
superior  in  Plot  5  but  scarcely  sufficient  to  account  for  the  differ- 
ence in  growth. 

Table  No.  3. 

Average  Annual  Yield  Per  Tree. 
Number  of  Apples. 


Year. 

Plot  1 

Plot  4 

Plot  5 

Sod. 

Tillage. 

Tillage  with  cover  crop. 

1908 

467 

105 

77 

1909 

95 

106 

80 

1910 

481 

1859 

2381 

1911 

795 

549 

99 

1912 

376 

2105 

2162 

1913 

734 

371 

99 

1914 

270 

2859 

2737 

1915 

No  crop  d 

lie  to  a  freeze 

Average 

459 

1136 

1091 

As  regards  yield  it  will  be  noticed  that  Plot  1  remains  the  lowest 
as  was  true  with  growth,  while  Plot  4  shows  a  little  higher  yield 


8 


N.    H.    AGR.    EXPERIMENT   STATION. 


[Bulletin  11 


than  Plot  5,  indicating  that  both  plots  have  been  receiving  suffi- 
cient supplies  of  available  food  materials  for  fruit  production. 

MOISTURE  AND  NITRATE  DETERMINATIONS. 

Soil  samples  were  taken  weekly  during  most  of  the  growing 
season  for  four  years.  The  surface  soil  is  taken  from  7  to  9  inches 
(or  a  little  more)  depending  on  its  depth  and  the  subsoil  is  taken 
from  that  point  to  3  feet.  Three  samples  are  taken  from  each 
plot  and  after  thoroughly  mixing,  a  pint  sample  is  taken  for 
analysis.  Moisture  is  determined  by  oven  drying  a  50  gram  sam- 
ple at  close  to  100°  C.  Nitrates  are  determined  according  to  the 
method  described  in  Bulletin  No.  31,  U.  S.  Dept.  of  Agriculture, 
Bureau  of  Soils.  The  following  tables  show  the  average  per- 
centage of  moisture  and  nitrates  (parts  per  million  of  dry  soil) 
found  each  week  during  the  growing  season  for  four  years  under 
the  various  treatments  heretofore  mentioned. 

Table  No.  4. 

Summary  of  Moisture  Determinations. 

Average  per  Plot.     Percentage. 


Surface  soil. 


Year. 

Plot  1 
Sod. 

Plot  4 
Tillage. 

Plot  5 
Tillage  with  cover  crops. 

1913 
1914 
1915 
1916 

16.02 

18.87 
25.63 
20.48 

13.69 
13.39 
19.29 
16.45 

14.20 
15.03 
20.82 
21.31 

Average 

20.25 

15.70 

17.84 

Subsoil. 


1913 
1914 
1915 
1916 

10.98 
14.14 
14.26 
14.82 

9.06 

9.78 

14.03 

12.74 

8.93 
10.26 
13.33 
13.24 

Average 

13.55 

11.40 

11.44 

October,  '16]  NITRATES    IN    ORCHARD    SOILS.  9 

Table  No.  5. 

Summary   of  Nitrate   Determinations,    Water  Soluble   Parts   per 
Million   of  Dry  Soil. 

Average  per  Plot. 
Surface  soil. 


Year. 

Plot  1 

Sod. 

Plot  4 
Tillage. 

Plot  5 
Tillage  with  cover  cop. 

1913 
1914 
1915 
1916 

2.64 
4.41 
2.09 
3.58 

18.25 
14.01 
21.05 
16.29 

38.37 
37.27 
18.75 
41.26 

Average 

3.18 

17.40 

33.91 

Subsoil. 


1913 
1914 
1915 
1916 

1.55 
3.56 
1.51 

2.18 

6.90 

6.62 

10.76 

5.05 

6.87 

10.81 

6.88 

8.05 

Average 

2.20 

7.33 

8.15 

From  the  above  data  it  will  be  seen  that  the  amount  of  nitrates 
recovered  in  the  soil  samples  under  sod  is  considerably  reduced 
as  compared  with  Plots  4  and  5.  The  ratio  of  nitrates  between 
sod,  tillage  and  tillage  with  cover  crops  is  as  1:5.4:10.6  in  the 
surface  soil  and  in  the  subsoil  as  1:3.3:3.7.  At  no  time  during 
the  experiments  have  we  obtained  a  sample  under  sod  that  showed 
more  than  14.78  parts  nitrates  per  million  and  the  average  for 
the  four  years  is  3.18  p. p.m.,  while  for  clean  tillage  it  has  gone  as 
high  as  63  p. p.m.  with  an  average  of  17.40  p. p.m.,  and  for  tillage 
plus  a  leguminous  cover  crop  it  has  shown  as  high  as  132  p.p.m. 
and  the  average  is  33.91  p.p.m.  for  the  four  years. 


10 


N.    H.    AGR.    EXPERIMENT    STATION. 


[Bulletin  11 


d  (Si 


lll^[^l^F^:t: 


-6 
5? 


I      -  I 


October,  '16] 


NITRATES    IN    ORCHARD    SOILS, 


11 


O  ^ 


fni^S 


-9    -^ny 


oi 


SI 

Tt 


J L 


12 


N.    H.    AGR.    EXPERIMENT    STATION. 


[Bulletin  11 


"  -S  ><i 


October,  '16] 


NITRATES    I\    ORCHARD    SOILS. 


13 


92 


'■''■■^ 


/iii 


14 


N.    H.    AGR.    EXPERIMENT   STATION. 


[Bulletin  11 


CO 

s, 

PL, 

m 

1 

CO 

oi 

3 

(N-^COTjHrHtOCOOCOO-^iOOOt^iM 

id 

s 

^ 

ICO(M0OCOiO-*Clt^iOCD        (Mt^CO^ 
JiO-*rHt^^,-i(MC)l>O(M00(Nt-O 

OJ 

f<TfCO^CO<Mt^OCDC<iTt<^iOa5t^C» 

5COO        OtXMCOiO        Tt<        (M 

iTiH»ot>^TtH.-i^(£)C»oO'*coooO'* 
-ococoiooOr-Hooocncoo^cocoio 

00 

CO 

^^.-H(M(M'*CD(MOC0C0t>O'*'*(M 

CO 

Tj^ 

s 

O  00  CT)  ^  (N  t^  iCi  00 '^i  00  i-H              IOCS! 

^ooTt^oa50(^^'*^^oooc^'-||£lco 

50iCOaiCO(MGOCl'*00(M.-it^<NiOt> 

i 

CO 

-  CO  ^  "*  iM  >*  CD  Tj<  CD  CO  O  00  CO  Tj<        I> 

-■ 

s 

1 
1 

1 

2 

lOO                                                               00 

TfH  oo  ^  1-H  00 ':*<      o              o<N»oa2 

i-HiOiCiO-*00(MCO'-H-H(MCO-*,-H 

]  t^^t^cociiooooo^oo^coojcooo 

jlOlM                  '^  t^  CO  CO  TjH  rH  (N  ,-H  (M  CO 

g 

11 

>d 

0.-H(M                                          O        W^iC 

jT-io^-^aJocooocot^ooc^oOT-no 

CO  CO  ■*  O  iC  (N  I>  CO  CO  (M  CO  CO        CO  1-1 

c<- 

CoSrHWC^S^^S^^ScoSrofo 

CO 
00 

CO 

1 

^?^^^^?^^^^u^§^^^ 

■^ 

a 
c^ 

cr 

O        (N 
CDOOGOCOCOCD<M^Ort<COCD<NCOCO 
O.-H-<jH,-Ht^c0(MC0T-i,-(,-iO00OcD 

00 

r-c<>co^oO'*co-*t^ocoi>-05<Nio 

^^^^          r->          (>,  CO  CO  rt<  rH  ^  ^  rH 

CO(N>0<:D        OiO  OcO  O  ^  CO  (N  020 
GOCOCOCNCO   a,00Olt^COCS|CO(M^T-HCO 
t^(Ma5t^CD   gOOC0(Nt^C005C0t^C0 

6 
5 

a. 

-HOOiOtMClCOCOOCDCOOt^COOO 
— 1  .-i(N               .-H  (N  CO        ^  (M  <M        ^  (M 

t      1     I 

> 

<1 

October,  '16] 


NITRATES    IN    ORCHARD    SOILS. 


15 


^  ^ 


o 
Ph 

1 

5 

(N 

O  t^  t^  rH  iXKM  CO  00  (M  00  CO  lO  T(<        O 
0005CCOO^JO(N05000i^O<NS 

2 

ococoeoo5C^Tj^osroodcoo6(N(N05 

-■ 

C<)O(MXOO<M000C'X00O-* 
-.QOCOO^^JXcC>0-H-SH-,H^Ot-C^ 

i 

i^Iz^SSSS^^^*^^^'^^^^*^ 

iC 

OcDaJC^C0(NiM(MC0OO'*O 

00 

i>xa>-Hoa5c»c:^oit^t^t>oiooot^ 

^ 

O--D'^00O-«J<^Q0->*(NO;DO 
O-t<Tj<t^Oi0i0l^00tic0^05T}<        t^ 
O31O00t^t>l^C^Ot>CCiO^(N00Q0 

C5 

OC^Ci'-O'-OOOOOOTOOOlCOOOOJOO 

- 

00  o  Tjt  CO  c^  00  •*  X      :o<stj<oo 

I^CnOOOCICOCfll^OOt^OOOOO        CD 

cc.ou:)coooooorabwc^^coS 

d 

-2 
o 

i 

'3 
m 

I 
1 

ci 

t^COiOt^itTXNC^QOOO^cOOOOOiO 

2 

OOit^GOCOt^GOiOvDCOO^OOCDO 

^C^rtHOCOCCt^--I>COCOT}<TtHO'*<N-<l< 

CO 

Sii5g§§8?2^5^goSS-S 

00 

2J^122^2!S2!;i;22"^^°'*"'"' 

iOO2O5C0^iOC5C0l-'Ma>--HCO(N        ^ 
iO05C000CO'#f0'-<^iOO<Nrt<i:D-<4<(N 

CD 

cc 

22I2S^212223E32'^'^"^'^'^'^ 

siisl&s?sgs^f^^§o§ 

i 

CD 

(MC^,  ^^^^        ^^^^        ^^C^C^ 

^ 

3 
i 

> 

16 


N.    H.    EXPERIMENT    STATION. 


[Bulletin  11 


-2 
o 

1 

^ 

CC>0(M05t^fCOcDeCO^-*t^'-(0-J(M52 
»OiCC0C0iO.-lC0-*t^O5Tj<00iO<£)i0c0O 

eocoo>oooc^coo5t^'-i'-iOcoTt<c^cocc 

- 

ii^§ss3isgi:s2^§§gi 

CO 

^^^§^g^2:2i^??^2g2:^^ 

lO 

DO^iOOt^        05C0                                 O"-!         lO 
3CO^IMOO>«D'^i-H^(MOCOCD.-(GOiOiCi 
^'-HO(^^TJ^C0l0Tt^C0Tt^C0:0^'-(t^C0C0r}^ 

CO 
00 
o 

•^ 

5 

Tt^ 

C 
C 

■JCNOIOOOCD        OKNOOOJ        COOOIMCOO 
OOOCDCO>OOfOTt<cDOiOO-*OiiOiOCO(MrH 

CD 
CO 

1. 

4^t^OOt^OO-^eOCO-*OiOOC^OO(MrtHcD 

-a, 

-■ 

»0                                                                                 --1  (M 

-a --r  lo -*  (N  o  CO  lo -*  ■*  (N  00      .-iiMOi^co 

DiOr-(C3-;t<t^02iOt^'*(MGOOi00002C50 

CO 

1  = 

ll 

1    ^ 

^r-iC-5t^05JOOCOCOiCiOiO.-i 

o 

X 
1 

m 

C^ 

CO              t^ '^  O  CD  CO  t^ '^t^  (N  CO  lO  05  ^  00 

COTt<lMCOr^(MOr-HCOCOCClTt<05lO(MOCO 

o 

O-KMCDt^^cOCnt^lM^CDOOOOOlOOCOCD 

OGOtr)OTfi(Mi-H,-icot^^cDco.-HTi<,-i 

- 

.-Hi0C0T-iOOOc0(MCD(X)l>05i0t^rtHi-l 

(Mi005Q0O'-HO(Mt^Ot>OC00i^05'-i 
00!Mt^^GO-*(MiOiOOi(MiOiCOTt<OT-( 

id 

^ 

DOO(MTt<OOOOOOTtH(M(NOfOO'-iCOT-H,-i 
-O^OOiOiOCOCOOlcDiOcOt^cDOOOOCO 

s 
^ 

^ 

s 

.iOOO.-iTt<COQOt^i-it>OOiO(MiOOOO.-H--H 
M^OOCOC<l'-HCOiMiOCOCT)COCO'#t-HCO(N 

TJH 

If 

^      CO                   t--      CO                   lo      -^  t^ 

D(M(N00(M<r>t^(NOc000COTtH.-HC»iOO202 
5(r^GO(N'-HkCTj<cOCOOrt<02(MCOOO'000(N 

CO 
o 

H01lOt^.-lrH-r#Tt<lOaiC»(M'*lOC0a3l0kO 

-■ 

Of 

c 

1  coo  ^  00  00  00 

5  ,-H  Oi  CD  CO  00  O 

t^                       c;i  lo 

GOcDTiHt^aiOcDcDOO 

r>-i— ICO-— ii>coo5t^O'* 

-*05C00iI>(NOt^^t> 

■* 
■* 

3  CO  iM  CO  lO  CD  lO 

00      cotOTf -*,-( 

< 

s 
5 

5  ■*  ^  00  lo  (^^  05  c: 

2COOCDCOOI^COO-*05 

1    1  1 

t 

< 

October,  '16] 


NITRATES    IN    ORCHARD    SOILS. 


17 


5£ 

P 


1 

1 

1 

^ 

ss?S§§g??2:2;g^S2?ggg 

o 

C2^O00C;2<N(NOOt^t^aD0000r-<0Cl 

Tt<00t>.I>a5t^(NCOO5Ol^.-lO5t^r=!c<l 

00 
(N 

c 

c^oo<ct^oo--.05air-ico^.-H(Nco^ 

c 

^gj^SBSg2?ssg-2:gs^^s§s§ 

e 

ROiOOiOSOJOOrHGOaJ^OOOOOCOOOOl 

c 

00 

a 

5C005iOr~-^.-ia0O00C:t^0^(NOi(MC-.  t^ 

c^ 

f 

'o 

1 

3 

C:O>0Tt<C0iMTj<t^^.0(MC^iCt^Tt<C 

'O 

^§§2:S$?S§^j£2:52§gS 

^ 

lO 

t^iOrt<eO":iOOOCDCOri<Tt<CO^CDCCi-H 

OO^COOOOOii-iOC^Ot^C^iOiCiO 

o 

o 

t^COf0(NCOO3t^0it^>CC0r-iiOt--t-HCO 

■*" 

g 

C^ 

coc<i^'Mc<:)'^^i.o-H^fO(MiomiMec^. 

- 

oooor^Oi(N»o^050oooooeoo5oo»OTjH 

00 

^?^222^?5i^2l:2§2g2;^°^ 

a 
1 

> 

So 
> 

18 


N.    H.    AGR.    EXPERIMENT    STATION. 


[Bulletin  11 


1 

1 
1 

<N 

rHooTt<i:^coo2,-iioa>0(M-*-<*r-(ioroi-H»oio 

=^232gg^g52?^^^?5?^^'^'^"''^^'^ 

d 

00 

CO 

^  CO  ^  ^  (M  r-(  <M  --<  CO  (M          rH 

lO 

CC        OO  C^  'i^  iM  t^ 
t^T-icOO500C^cO«:)t^C<)^'*COCO'*'*rt<00 

^ 

d 

oocot^a5^iocot^cot^t^rH,-Hcoc<nooiT-(co 

C3i 

^ 

t^OOOSOC^COOit^iMrOOOOCOOOOrHGO 

CO 

o 

1    , 

Tt<C»05THOiO"*CO(MOC»t^COt^r-i(£i|>COCO 

-S-3 

- 

i-H        O                          Cq  00002                                lO 

i 

! 
1 

cvi 

.^S;g:SEsSSS§;oSgSS:^g§gg 

1  a 

t^i-icCKMiOiOOO^t^COOOOSr-iOiMCSCOC^I^ 

^CD00(M(Nr-l<NCOCOrH(NC-J,-HC^ 

- 

t^O'i<OiOOO^COiO'-lcOrHCOQO^O'^'-i 

00 
CD 

(Ma50ir).-4rHcofoco(M(Mca'-HC^.-i 

" 

t^  CO  t--  o      c<i 

cococoiO'^cooaKMfMajQO.-Hcocooooco 
cDio»ot^ait>coioo5iocoi>.-ir-ioooi>coi> 

00 

COC^J-HOOi'^t^OO^COOt-iMOOCOOlOCDt^ 

r-HOilOCD                                 y-f          r-(--l,-l 

'^ 

coooocO'*Tt<o      ocr)r-^^^G005<^l(^^t005'-^ 

- 

0  00«MO   gcO^Ot^'-iOOCOOXNiOOOiC 

fOrHOSi-ioocD  ^■^oco'Oi^eoaioOrt-*o5'-i 

(M(N        tH              i3 --I  CO  CO  tJ^  tJH  (M  ^  ,-1 -^  t-h        (M 

<N 

c 

i 

I 

l0C0C0Ot>^.-HG0'*rH00lCr-(00tXM03C0-* 
rH  ,-(  (M  CO         --I  C^  C^         ^  ^  c^i                _  cvj  cv)         ^ 

M  1   1   1    1 

< 

October,  '16] 


NITRATES    IN    ORCHARD    SOILS. 


19 


1 

1 

1 

IS 

? 

-2 

c 

Oh 
1 

c^ 

o§§[^S§^5588S5J?Qf2^^§g22^ 

^m050rO'*CR'OC^Tt(C^iOt^OiOCOlMiOCC 

^ 

c.^^?2?22^SSI^^gg§g^f;?j:;;^§ 

CO 

CO 

■-tOCOQO— i(MCO.-i^COC^COTt<TjHCs)TtH.-iCCCO 

T}< 

CO 

CO 

CO 

r-(fOOGOO-*0!MO-t<lCCOOT-HlOTj4t^Cit^ 

cor^i§^^s?^gsp^2§sg^?32^^ 

s 

■* 

05-0  '-iCO'*iOC<lCC(N>OTt<t^C^iOCOiOCOCDTj< 

- 

l^  Ci  CO  O  ^  O  02  O  "O  CC  C  ^  CO  t-  I^  cr.  ,-t  o 

1— I 

CO'^OOCOCO'^OTt^O-^CC^OiOiOiO'^f.-H 

6 

o 

1 

3 

c-i 

^g§Sg^s^5aSSf:§gggSI^^ 

CO 

CO 

1 

e1 

S222g5g52g^?5?3?^g5?3^§^i:?^g 

^ 

g5 !:;  ^  ^  g^c^' ?3' j:^  ?J  J$?  ?^' g{' g  2  2  ?3  2  g  § 

2 

■o 

s 
s 

-r 

c.;^S^^2SS§§2S§^-2§2§S 

05 

222l:?JgJ2g;jg^?^?^g2222S2 

- 

8&[;5SK^5§rt:ss§§2^iK§g^ 

?5Sg52^g^S?5^^^S^g^Sg5^5:5 

a, 
P 

11   §    1    1      t^ 

2 

> 

20 


N.    H.    AGR.    EXPERIMENT    STATION. 


[Bulletin  11 


o 

6 

^ 

^ 

o 

^ 

^^ 

3 

g 

^ 

< 

.2 

JtH 

■^ 

O) 

g 

a 

•<~i 

s 

[^^ 

Lh 

■w 

cri 

Q 

Pk 

o 

1 

^ 

§j:gSgF:s§§28g^ 

s 

t^C<l'*TfcOt^^OO'*iCCOO 

^^ 

o 

lO 

o 
00 

iO.-HiOiLOiOiOQ0050tOCDO^ 

'^ 

§SS5S^§SSSSS§§ 

crxN'tcccofOccccxMicr-ooo 

00 

CM 

.  C^  CCIM  !M  <M --1              --H  (M  T-H  CO  CO 

o 

1 

(^i 

"*  <N  CO        05  »0  O  C^  O  02  CC  05  (M 
Ot^iO        CO  CO  O  (M  CO  0>  Ol^  CO 

^ 
g 

- 

^5B^gS5?^2^2;gss 

00 

OOOOiO!M'*t^GOCO^O'OcOiO 
^OICO'OcOCaGOiOQOI^COt^rt^ 

§ 

OiO.-i»OCOC)^OCOO'*!MiO 
CicOCOt^'*(M'#»O^COOiMt^ 

^ 

^ 

^        CO  05  <M  »0  CO -rfH  >0  CO  r- CO  C<1 

§§^^sfej;5^^s§§;::g 

CO 

GOTt<'*>-i.-HiooO'*050coi>co 

.— 11— It-Ht-Ht— li— 1          C^C<)C>^CO 

- 

oot^i>coicic<Nt-iiMeococooo 
oot^ooiocO'*c<iioa>(N'*o 

CO 

CD  CCl^  CO  cow  t-H  1-1  rH(N  •*•*•* 

f 

5 

^i-i00iC(NO>CO(N05CDC0OiO 
CO(M(M        t-i  i-H  IM              i-ilMCO 

II  t   1    1 

October,    16] 


NITRATES    IN    ORCHARD    SOILS. 


21 


s 

Oh 

1 
3 

m 

!M" 

'-DCMCviOXt^Tf-^rJ-^^OO 

2 

-*C002C5t^"^t^XCDiCiC:OiO 

'*cDMa:cviooox:CO-*05C: 

CO 

(MOCCrOiOTtHt^'MLOCOeO-^ 

<d 

2  ;^  2  2  2  2  if:  2  -2;  S^'  2  ~"^ 

§ 

-OC^IQO-*<N1DOO'*C:00(N« 

1 
C 

1  S) 

^1 

2^2z:H2£22221S2°^'*'^ 

- 

-^'^(Mxc^iTtooaOTt-^oiTf 

^ 
•* 

C5t^lCOt-^T)<M-HXlOTfT)< 

"5 

c 

04 

■*^"*C^!MXXOC:MiCXX 

?5 

C^(NC^C^C^'NC^C^'(>l?5?3c^§ 

1 
1 

- 

OcCC:^C:C:;r:-^XTfxt^!M 

?^^?^?3?^S;^?^?jg^5^?5 

^ 

X^C:-*T»';000  0)OwOcO 

CO 

IS 

2?:5?5^?52^g?5g2g?:3 

'*C^"*XX-*^XXXO'M01 

CO 

rMO»cr^eo-<4<(Mcox>Cfcx»o 

■*x-rc-r-r3c;~u;-f  —  1^ 

^ 

32^^c5?52S?J22i^g2 

§ 

3 

> 

22  N.    H.    AGR.    EXPERIMENT    STATION.  [Bulletin  11 

The  summer  of  1915  was  very  wet  and  as  a  consequence  the 
nitrates  recovered  in  our  samples  were  low  as  compared  with 
other  years.  This  can  be  well  seen  on  Charts  3  and  8,  as  the 
heavy  rains  began  July  6.  The  curves  drop  down  at  that  time 
and  remain  low  throughout  the  rainy  period  without  much  dif- 
ference between  the  plots.  This  is  likely  due  to  two  things,  first, 
nitrification  was  probably  not  so  rapid  when  the  soil  was  very 
high  in  moisture,  and  second,  what  nitrates  were  formed  were 
readily  leached  out.  Plot  5  here  fell  a  little  below  Plot  4  with  a 
difference  in  favor  of  the  latter  of  about  2  p. p.m. 

This  evidence  seemed  to  warrant  the  position  that  the  forma- 
tion of  nitrates  is  greatly  reduced  in  a  sod  orchard  and  from  a 
fertility  standpoint  is  the  first  limiting  factor.  Not  only  does 
the  growth  average  about  half  as  great  as  where  a  good  system 
of  culture  is  practiced,  i.e.,  as  4.80:8.83,  but  also  we  find  a  smaller 
size  of  the  leaves  and  a  poor  color,  denoting  an  insufficient  amount 
of  available  nitrogen.  That  the  lack  of  vigor  is  due  to  an  insuffi- 
cient supply  of  moisture  cannot  be  advanced  for  it  has  been  some- 
what of  a  surprise  throughout  the  entire  experiment  that  there 
was  a  higher  per  cent  of  moisture  in  the  sod  plot  than  in  the  adja- 
cent tilled  ones. 

NITRIFICATION  UNDER  SOD. 

During  the  past  season  we  have  attempted  to  determine  the 
approximate  amount  of  nitrates  formed  under  sod.  In  order  to 
determine  this  a  small  plat  3  feet  square  was  selected  in  Plot  1 
(the  sod  plot)  quite  near  to  the  point  where  the  soil  samples  had 
been  previously  taken,  and  the  sod  carefully  removed  without 
stirring  the  soil  beneath.  Another  plat  of  equal  size  was  selected 
close  to  the  first  and  after  the  sod  was  likewise  removed  the  soil 
was  spaded  to  the  depth  of  the  surface  soil  and  cultivated  with  a 
hoe  weekly.  This  gave  three  conditions  within  the  original  sod 
plot:  (1)  sod;  (2)  bare  soil;  (3)  bare  soil,  stirred  each  week. 
While  the  bare  plat  would  not  represent  the  exact  conditions 
under  sod,  yet  it  seems  to  be  as  near  that  condition  as  is  practical 
to  obtain  in  the  field.  While  this  phase  of  the  work  was  not 
begun  until  the  middle  of  summer  the  determinations  seem  to 
throw  light  on  the  question. 


•October,   'Ifil  NITRATES    IN    ORCHARD    SOILS. 

Table  No.  14. 

Nitrates,  Part.'<  per  Milh'on  of  Dry  Soil. 

Surface  k^oil. 


23 


July 
24. 

'Si' 

Auk. 

Aug. 

14. 

■1?,' 

Aug. 

28. 

Sept. 
4. 

Sept. 

'T 

Average 
.\ug.  7  to 
Sept.  23. 

Sod 

Bare 

TiUed 

2,599 
2.575 

1.871 
2.615 

2 .  800 
4.717 
10.. 575 

2 .  (itiS 

3 .  330 
10.002 

3.748 
11.112 
24 , 9(i9 

3.075 
10.755 
51.021 

4.27 
7 .  856 
65 . 553 

.568 
1 .  923 
8. 332 

1.464 
2.380 
8.820 

2.656 
6.010 
26.469 

Table  No.  15. 

MoiMure,  Percentage. 

Surface  Soil. 


July 
24. 

July 
31. 

Aug. 

7. 

Aug. 
14. 

Aug. 
21. 

^l- 

Sept. 
4. 

Sept. 

Sept. 
23. 

Average 
Aug.  7  to 
Sept.  23. 

Sod 

Bare 

Tilled 

27.0 
26.4 

26.8 

27.4 

25.0 
24.4 
24.6 

25.2 
24.4 
24.6 

22.0 

21.2 
22.2 

24.9 
25.7 
25.8 

21.8 
22.8 
22,8 

27.0 
27.0 
27,5 

26,5 
26.5 
26.5 

24.6 
24.6 
24.8 

From  the  tal)le  it  will  l)e  seen  that  there  is  practically  no  dif- 
ference in  moisture  to  account  for  variations  in  nitrates.  It 
will  also  be  seen  that  the  amount  of  nitrates  formed  under  the 
sod  would  be  approximately  the  amount  shown  on  the  bare  soil 
but  where  this  same  soil  is  stirred  nitrification  progresses  at  a 
much  greater  rate.  So  it  would  seem  to  indicate  that  nitrates 
are  reduced  under  sod  to  a  marked  degree  as  compared  with  the 
same  soil  under  tillage.  The  ratio  between  the  three  small  plats 
is  as  follows : 


Sod. 
1 


Bare. 
2.2 


Tilled. 
10. 


Later  in  the  season  another  sod  orchard  of  Baldwin  trees  was 
used  to  duplicate  the  experiment.  Determinations  of  nitrates 
and  moisture  had  been  made  throughout  the  season  on  two  un- 
fertilized rows  under  the  sod  and  gave  a  weekly  average  for  the 
season  as  follows: 


24 


N.    H.    AGR.    EXPERIMENT    STATION. 


[Bulletin  II 


^  ° 


October,  '16] 


NITRATES    IN    ORCHARD    SOILS. 


25 


Average  Moisture  atid  Nitrates  in  Second  Orchard,  1916. 
Surface  Soil. 


Nitrates. 

Moisture. 

Row  4 

3.55 

3.28 

22  98 

Row  8 

22  69 

After  small  plats  similar  to  the  ones  described  in  Plot  1  were 
made  on  Row  4  determinations  were  made  which  gave  the  fol- 
lowing results: 

Table  No   16. 


Moisture,  percentage. 

Nitrates,  p. p.m. 

Aug. 
21. 

*« 

Sept. 

^^ 

ir 

... 

'A' 

•\"|- 

Sept. 
4. 

"It 

Sept. 
23. 

Av. 

Sod 

Bare  .... 
Tilled.    .  . 

22.8    26.0  i24.8  128. 
23.6    26.1  124.4    27.5 
21.4    20.1    23.0    28.5 

29. 
27. 
27. 

26.12 
25.72 
25.20 

2.980!  3.838 
9.046    6.5.50 
11.657  13.009 

4.606 
6 .  382 
29 . 880 

.857 

.901 

3 .  702 

1.03 
1.166 
3.33 

2.662 
4.809 
12.049 

No  rains  fell  during  the  first  few  weeks  of  these  observations 
and  the  nitrates  accumulated  as  the  weeks  progressed  and  formed 
a  rapidly  ascending  curve  where  the  soil  was  stirred,  but  on  Sept. 
15,  1.42  inches  and  Sept.  18  1.10  inches  of  rain  fell  and  the  curve 
drops  down  again  as  the  nitrates  had  washed  out. 

These  results  do  not  extend  over  as  long  a  period  as  might  be 
desirable  but  from  our  experience  over  four  years  in  the  orchard 
they  seem  to  duplicate  the  results  obtained  there. 

EFFECT  OF  LIME  ON  NITRIFICATION. 

It  has  been  shown  a  number  of  times  that  when  lime  is  applied 
to  soil  it  will  increase  nitrification.  Four  years'  results  on  a 
cultivated  orchard  show  a  greater  average  amount  of  nitrates 
recovered  in  the  samples  where  the  lime  was  applied.  However, 
nitrates  are  quite  variable  and  seem  to  be  readily  affected  by 
weather  conditions.  Especially  where  fertilizers  have  been  ap- 
plied do  we  find  irregularities  apparently  due  to  obtaining  some 
of  the  fertilizers  in  the  sample  occasionally.     So  that  any  par- 


26 


N.  II.  a(;r.  experiment  station. 


[Bulletin  ir 


CO   e 

^  2  ^ 


!liliMiiMrSI^#lJ 


vz 

tz 

79    -any 

-z  Mp-z 
1>z 


i 


rtif! 


■ft 


■^4^. 


tiH 


1^ 


s 


w 


i 


^i 


)tf 


il 


J \ I      I 


iilis 


October,  'Ifi] 


NITRATES    IN    ORCHARD    SOILS. 


27 


|ie^y,h:[iM:|Tfi^:::h^a::::!::-:!:-:!-^ii:;i|^^ 


t^    ©J 


dc2 


m^m^. 


-9    -in. 
Of 

-6 

T 

8T 


ijg-T   Xter 


''^' 


X- 


28 


N.    H.    AGR.    EXPERIMENT    STATION. 


[Bulletin  II 


H  S  ^ 
rt  7  ^ 

DC    S  ~ 


October,  '16] 


NITRATES    IN    ORCHARD    SOILS. 


29 


mSi-'\  :  i  H:lna^^fen::.l:-=:t:Htii^:f:^mif^rt-^--t™t::n^-::f:r;tf:.n}:.:4:t^;.:^44i 


•'^    I   ®i 

CO  e 
< 


h  of 
6 

6t 
ZX 


^"'frun 


J \ I \ I L 


tVI  Ci 


30 


N.    H,    AGR.    EXPERIMENT   STATION. 


[Bulletin  11 


ticular  determination  or  even  the  average  for  one  season  is  not 
very  satisfactory  but  where  four  consecutive  years  are  consid- 
ered, the  average  can  be  pretty  well  relied  upon.  The  following 
tables  show  the  nitrate  and  moisture  determinations: 


Table  No.  17. 

Summary  of  Nitrate  and  Moisture  Determinations. 
Limed  and  Unlimed  Plots. 

Nitrates. 


Plot  11— Limed. 

Plot  12— Unhmed. 

Year. 

Surface 
soil. 

Subsoil. 

Surface 
soil. 

Subsoil. 

1913 
1914 
1915 
1916 

82.33 
82.46 
29.98 

98.48 

19.60 
23.43 
13.78 
24.10 

57.46 
57.09 
24.26 
80.36 

6.16 
15.21 
17.24 
11.56 

Average 

73.31 

20.23 

54.79 

12.54 

Table  No.  18. 
Moisture. 


Plot  11— Limed. 

Plot  12— Unhmed. 

Year. 

Surface 
soil. 

Subsoil. 

Surface 
soil. 

Subsoil. 

1913 
1914 
1915 
1916 

19.14 
15.42 
21.19 
22.47 

'  11.92 
10.28 
12.33 
13.72 

16.75 
15.99 
21.38 
23.98 

11.22 
10.50 
13.64 
16.72 

Average 

19.55 

12.06 

19.52 

13.02 

rmmry 


J  mARY 


October,  '16]  NITRATES   IN   ORCHARD   SOILS.  31 

SUMMARY. 

1.  Nitrification  proceeded  slowly  on  the  sod  plots  of  these 
orchards. 

2.  Stirring  the  soil  readily  increased  the  rate  of  nitrification. 

3.  Under  a  good  system  of  tillage  nitrates  were  usually  present 
in  excess  of  the  needs  of  the  trees. 

4.  Lime  consistently  increased  nitrification. 

5.  Moisture  was  not  the  limiting  factor  in  the  sod  plots. 


UBRAkf 
M.  C.  State  College 


'^yi'.'^'S 


T 


fe*i 


up^ 


•ill 


-v    *>«■ 


^^.^'i:^? 


}^iMMkA 


